Carding machine screen



Oct. 20, 1970 v w. L. WALKER 3,534,444

CARDING MACHINE SCREEN Filed NOV. 29, 1968 Ivy. 4'

INVENTOR WILLIAML. WALKER ATTORNE Y5 United States Patent US. Cl. 1995 1Claim ABSTRACT OF THE DISCLOSURE A card screen is provided whichincludes a curved frame. A number of elongated aligned flat transversemembers are carried by the frame. Spaces are defined between adjacentedges of the flat members which are relatively narrow in relation to theflat members and legs extend outwardly from the edges away from the maincylinder substantially normal to the flat members. The total areadefined by the spaces is just sufiicient to prevent blow-out at thesides of the card. The legs extend outwardly for a sufficient distanceto prevent substantial recirculation of air which has been blown outthrough the spaces back into the space adjacent the main cylinder.

This is a continuation-impart of my copending application bearing Ser.No. 684,289, entitled Carding Machine Screen, filed Nov. 20, 1967 nowabandoned.

This invention relates to an improved card screen producing an improvedweb by reducing the turbulence of air currents generated adjacent themain cylinder and minimizing the possibility of nep build-up.

Turbulence of the air currents generated by the high speed at which cardcylinders rotate has long produced adverse affects on the web. Suchaffects take the form of excess waste, neps, chokes and variations inthe web thickness. Many attempts have been made to ameliorate suchconditions. Perforated screens have been provided with openings in fiatstock, but such do not materially reduce the formation of neps and donot substantially improve other aspects of carding. Screens constructedof triangular bars are thought to permit recirculation of air exhaustedthrough the spaces therebetween. In any event, such have not solved theproblem.

Accordingly, it is an important object of this invention to provide acard screen which will reduce variations in web thickness.

Another important object of the invention is to provide an improved cardscreen which will result in reduction in nep formation both from thestandpoint of number and size thereof.

Another object of the invention is to provide an improved card screenfor use under the main cylinder which will reduce the number of chokeson the nose of the front screen.

Another important object of the invention is the production of a clearerweb of much improved quality.

Another object of the invention is the reduction of lint formation onthe screen during carding and the reduction of overall waste duringcarding resulting in fewer damaged cylinders, dolfers and licker-ins.

A very important object of the invention is to increase the weight ofthe web produced while improving the quality thereof.

Another important object of the invention is the reduction of ends downon the card.

Another important object of the invention is to increase the amount offoreign matter exhausted under the card with a reduction of overall lintformation.

The construction designed to carry out the invention Patented Oct. 20,1970 ice will be hereinafter described, together with other featuresthereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingforming a part thereof, wherein an example of the invention is shown andwherein:

FIG. 1 is a schematic side elevation, with parts omitted and partsbroken away, illustrating a carding machine with a screen constructed inaccordance with the present invention installed thereon,

FIG. 2 is an enlarged perspective view illustrating a screen constructedin accordance with the present invention,

FIG. 3 is an enlarged sectional elevation taken on the line 3-3 in FIG.2 further illustrating such screen construction, and

FIG. 4 is an enlarged sectional elevation taken on the line 4-4 in FIG.2 further illustrating the screen con struction.

The drawing illustrates a screen for use beneath the main cylinder of atextile card constructed in accordance with the invention. The screenincludes a longitudinal frame A curved to conform to the curvature ofthe main cylinder. A plurality of elongated aligned flat transversemembers B are carried by the frame tangential to the curvature of theframe. The flat members B have adjacent edges defining spaces Ctherebetween. The spaces C are relatively narrow in relation to thewidth of the fiat members B. A plurality of transverse legs D extendoutwardly from the edges away from the main cylinder along the edges.The legs D are substantially normal to the fiat members B and areintegral therewith. The area defined by said spaces C is only slightlygreater than that area at which blow-out would begin to occur at thesides of the card, and the legs D extend outwardly for a sufiicientdistance to avoid appreciable recirculation of air which has beenexhausted through the spaces. It will be noted by reference to FIG. 2that relatively large imperforate portions are provided on the backscreen and front screen. The imperforate portion on the back screenportion is especially extensive.

A conventional carding machine is illustrated in FIG. 1 with the framebeing designated at 10. The frame carries the usual lickerin roll 11, amain cylinder 12 and a doffer cylinder 13. The frame A of the cardingmachine is attached by any conventional means which are partiallyillustrated at 14. A lickerin screen is illustrated at 15.

The frame A includes spaced curved side portions 16 and 17, each ofwhich has two segments, as illustrated at 16a and 16b. The frame members13 carrying the legs D are suitably attached to the frame members byinterfitting (FIG. 4) and soldering (not shown). The flat members B maybe slightly curved, as illustrated in FIG. 3, to conform generally tothe curvature of the card cylinder or they may be planer. It will beobserved that the flat members B are relatively wide and a dimension ofabout 3" has been found to be acceptable, although somewhat more or lessmay also be practical.

The spaces C are relatively narrow in relation to the width of the fiatmembers B and a spacing of about A has been found to be acceptable,although somewhat more or less may also be practical. It is importantthat the total area defined by the spaces C is only slightly greaterthan that area at which a blow-out would begin to occur at the sides ofthe card. This total area should be less than about 15% of the area ofthe entire screen. It has been found that 7 to 9 such spaces per screenproduces acceptable results, although somewhat more or less may also bepractical. In other words, the total area of such space is preferablyjust enough to permit sufficient air flow as to avoid substantialblow-out. The relatively large imperforate area on the back screen isillustrated at 16c, and the imperforate area on the front screen isillustrated at 1 6d. The imperforate portions extend over the majorportion of said screen and limit air flow.

The legs D extend outwardly from each edge of the fiat members B in adirection substantially normal thereto. By thus restricting the totalarea of the spaces C appreciable recirculation of air which has beenblown-out through the relatively few narrow spaces C due to limitedaccessibility of the screen therefor. An outward distance of to 1 hasbeen found acceptable for the legs although somewhat more or less mayalso be practical. The legs D take the form of a conventional sheetmetal hem wherein the metal is folded twice, as illustrated at 18 inFIG. 3. Contrary to what would have been expected, it has been foundthat a more uniform web is produced by carding machines equipped with ascreen constructed in accordance with the invention described above. Aclearer appearing web is produced while increasing the average grainweight thereof. The advantages enumerated hereinbefore are thought tooccur as a result of better control on the air currents produced duringcarding. Less air escapes through the screen and less turbulenceconditions are arrived at. No abrupt edges are presented which wouldencourage nep formation and a reduction of overall waste is achieved.Exhaustive field tests have proven that such results are achieved on allvarieties of stock and production rates.

While a preferred embodiment of the invention has been described usingspecific terms, such description is for illustrative purposes only, andit is to be understood that changes and variations may be made withoutdeparting from the spirit or scope of the following claim.

What is claimed is:

1. A screen for use beneath the main cylinder of a textile cardincluding,

(A) a longitudinal frame curved to generally conform to the curvature ofthe main cylinder,

(B) a relatively few elongated aligned substantially flat, relativelywide, transverse members carried by the frame substantially tangentialto the curvature thereof,

(C) a substantially imperforate end portion carried by said frameadjacent each end thereof extending over the major portion of saidscreen,

(D) said flat members being carried intermediate said imperforate endportions,

(E) said flat members having adjacent edges defining spacestherebetween,

(F) said spaces being relatively narrow in relation to the width of saidfiat members,

(G) a plurality of transverse legs extending outwardly from said flatmembers away from the main cylinder,

(H) said legs being integral with said flat members,

(I) said spaces defining a total area of space less than about 15% ofthe entire screen so that the area defined by said spaces is enough topermit suf- -ficient air flow as to avoid blow-out at the sides of thecard while avoiding appreciable recirculation of air which has beenexhausted through the spaces, and

(J) said legs extending outwardly from each of said edges substantiallynormal thereto.

References Cited UNITED STATES PATENTS Re. 8,313 7/1878 English 19-95233,221 10/1880 English 1995 538,200 4/1895 Rascoe l995 3,348,26810/1967 Jenkins 19-95 DORSEY NEWTON, Primary Examiner

